So now that we've covered what types of computer hardware make a good audio system, it's time to turn to how to get music in and out of the computer. It's time to talk about interfaces, those wonderful devices that connect music to an otherwise lifeless machine. Interfaces are pieces of hardware that connect to a computer to bring music in and out.

MIDI

MIDI interfaces are the simplest and least expensive interfaces for a computer. They come in many shapes and sizes, one for every need. You will want to get an interface that has one input for every piece of MIDI-enabled gear in your studio. The MIDI interface is shown in FIGURE 5-1.

FIGURE 5-1

Computer MIDI interface

Basic interfaces start around $35; an interface with more inputs will be more expensive. In terms of connections, MIDI interfaces come in a few flavors:

• Serial: Not very common now. This is a connection that attaches to a serial port on your computer.

• PCI MIDI interface: A card that sits inside the computer. Usually combines audio and MIDI.

• USB MIDI interface: A small rectangular port on the back or front of your computer.

• Firewire MIDI interface: Firewire, as it's known on the Mac, or IEEE 1394 as it's known in the Windows world, is a new connection that is becoming standard. Firewire interfaces usually combine audio and MIDI.

Getting Audio In and Out

In terms of routing audio in and out of your computer, you have to make some hard decisions about how many instruments you can record at once.

Simple interfaces that support one or two channels are relatively inexpensive. If you are looking to record eight simultaneous inputs, be prepared to pay more. Also key is the number of microphone inputs that the interfaces have. If you plan to record acoustic instruments such as piano, voice, or anything else that requires a microphone, you'll need a few microphone inputs (shown in FIGURE 5-2).

FIGURE 5-2

Computer recording interface

Just like MIDI interfaces, audio interfaces come in three basic forms:

• PCI: A card that sits inside your computer. A cable usually attaches from the card to a tabletop unit, called a breakout box, that contains the actual inputs. These are the most common audio interfaces.

• USB: USB makes it easy to move between computers, but sometimes it lacks the necessary speed to pipe audio in and out fast enough. This is why USB interfaces rarely exceed four inputs. If you're looking to record many sources, USB might not be for you. They do work well for smaller recording needs, and they are priced attractively. If you have a laptop, you don't have the PCI card option, so USB is a choice for you.

• Firewire: Firewire is much faster than USB and allows for a greater number of inputs. It's also more expensive than USB. Firewire is becoming a great option for mobile and home recording because of its high track counts and portability factor.